Water-insoluble monoazo pyridine dyes

ABSTRACT

Water-insoluble monoazo dyes of the formula ##SPC1## 
     Produced by reacting a diazotized amine of the benzene, naphthalene, diphenyl, diphenylmethane or heterocyclic series which is free from water solubilizing groups with the appropriate 6-hydroxy-2-pyridone and the utility thereof for the dyeing and printing of synthetic fabric materials to yellow to red shades having excellent fastness to light and sublimation.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 882,285, filed Dec. 4, 1969, now abandoned.

The present invention relates to new water-insoluble monoazo dyes of the formula ##SPC2##

Wherein R is the residue of a benzene, naphthalene, diphenyl, diphenylmethane or heterocyclic diazo component which is free from water-solubilizing groups; X is hydrogen, alkyl containing 1 to 6 carbon atoms, preferably methyl, alkoxycarbonylmethyl containing 3 to 9 carbon atoms, alkoxycarbonyl containing 2 to 7 carbon atoms, cyclohexyl, benzyl or phenyl; Y is cyano, nitroso, nitro, alkyl containing 1 to 6 carbon atoms, cyclohexyl, benzyl, phenyl, --COOR₁, --COR₂, ##EQU1## wherein R₁ is alkyl containing 1 to 6 carbon atoms; R₂ is alkyl containing 1 to 6 carbon atoms, cyclohexyl, benzyl, phenyl, methylphenyl, dimethylphenyl, methoxyphenyl or chlorophenyl; R₃ and R₄ are each hydrogen, alkyl or hydroxyalkyl containing 1 to 6 carbon atoms, alkoxyalkyl containing 2 to 7 carbon atoms, cyclohexyl, benzyl or phenyl and R₅ is --CH₂ --CH₂ --O--CH₂ --CH₂₋₋, --(CH₂)₆ -- or --CH₂ --CH₂ --NH--CH₂ --CH₂ -- and Z is alkyl containing 1 to 6 carbon atoms, alkenyl containing 2 to 6 carbon atoms, alkenyl containing 2 to 6 carbon atoms, mono- or dialkylaminoalkyl containing from 1 to 6 carbon atoms in each alkyl moiety, cyanoalkyl, hydroxyalkyl, ethanoyloxyalkyl, methoxyalkyl or phenoxyalkyl containing 1 to 6 carbon atoms in the alkyl moiety, cyclohexyl, benzyl, phenyl or substituted phenyl wherein the substituent is ##EQU2## wherein n is an integer of from 0 to 3 and R₁, R₂, R₃, R₄ and R₅ are as aforesaid.

When X, Y or Z is cyclohexyl, benzyl or phenyl, it may be substituted by one or more halogen atoms, lower alkyl or lower alkoxy radicals.

Preferred R moieties include phenyl, monosubstituted phenyl whose substituent is selected from the group consisting of chlorine, nitro --CO--CH₃, --CO-phenyl, --CH₂ --SO₂ --CH₃, --OSO₂ CH₃, -OSO₂ -phenyl, ##EQU3## --CONH₂, --CONHCH₃, ##EQU4## --SO₂ NH₂, --SO₂ --NHCH₃, ##EQU5## --SO₂ --NH-phenyl, ##EQU6## ##SPC3## or disubstituted phenyl whose two substituents are selected from the group consisting of chlorine, bromine, nitro and cyano or trichlorophenyl.

The dyestuffs of the present invention are obtained by coupling diazotized amines of the benzene, naphthalene, diphenyl, diphenylmethane or heterocyclic series which are free from water-solubilizing groups and have the general formula R.NH₂ with 6-hydroxy-2-pyridones of the general formula ##SPC4##

wherein X, Y and Z have the above-given meanings.

Diazo components of the general formula R.NH₂ are for example:

aniline,

2-, 3- or 4-amino-toluene,

3-amino-benzotrifluoride,

3- or 4-amino-1,2-dimethylbenzene,

2-, 4- or 5-amino-1,3-dimethylbenzene,

4-amino-1,3,5-trimethylbenzene,

2-, 3- or 4-amino-anisole,

2-, 3- or 4-amino-phenetole,

2-amino-1,4-dimethoxybenzene,

2-amino-1,4-diethoxybenzene,

2-, 3- or 4-amino-phenyl-β-hydroxy-ethyl ether,

2-, 3- or 4-amino-phenyl-β-hydroxy-n-propyl ether,

2-, 3- or 4-chloroaniline,

2-, 3- or 4-bromoamiline,

2,3-, 2,4-, 2,5- or 3,4-dichloroaniline,

2,5-dibromoaniline,

2,4,5-, 2,4,6-, 3,4,5- or 3,4,6-trichloroaniline,

3-, 4-, 5- or 6-chloro-2-amino-toluene,

4-chloro-3-amino-toluene,

2-chloro-4-amino-toluene,

5-chloro-2-amino-benzotrifluoride,

4,5- or4,6-dichloro-2-amino-toluene,

2,5- or 4,6-dichloro-3-amino-toluene

2,5- or 3,5-dichloro-4-amino-toluene,

4,5,6-trichloro-2-amino-toluene,

4-chloro-2-amino-1,3-dimethyl-benzene,

6-chloro-3-amino-anisole,

2-chloro-4-amino-anisole,

3-chloro-4-amino-anisole,

2-, 3- or 4-nitraniline,

3-nitro-4-amino-toluene,

5-nitro-4-amino-1,3-dimethylbenzene,

6-nitro-3-amino-anisole,

3-nitro-4-amino-anisole,

5-nitro-2-amino-phenetole,

2-nitro-4-amino-phenetole,

3-nitro-4-amino-phenetole,

5-nitro-2-amino-1,4-dimethoxy-benzene,

5-nitro-2-amino-1,4-diethoxy-benzene,

2-chloro-4-nitraniline,

2-bromo-4-nitraniline,

4-chloro-2-nitraniline,

4-bromo-2-nitraniline,

2,6-dichloro-4-nitraniline,

2,6-dibromo-4-nitraniline,

2,4-dinitraniline,

6-chloro-2,4-dinitraniline,

6-bromo-2,4-dinitraniline,

2,4,6-trinitraniline,

2-cyano-4-nitraniline,

4-cyano-3-nitraniline,

2-methylsulfonyl-4-nitraniline,

4-methylsulfonyl-2-nitraniline,

2-, 3- or 4-amino-acetophenone,

2-, 3- or 4-amino-benzophenone ethyl 2-, 3- or 4-amino-benzoate,

n-butyl 2-, 3- or 4-amino-benzoate,

cyclohexyl 2-, 3- or 4-amino-benzoate,

2-, 3- or 4-amino-benzamide,

2-, 3- or 4-amino-N-methyl-benzamide,

2-, 3- or 4-amino-N,N-dimethyl-benzamide,

N-(2-, 3- or 4-amino-benzoyl)-ethylenimine,

2-, 3- or 4-amino-N-isopropyl-benzamide,

2-, 3- or 4-amino-N,N-diethyl-benzamide,

2-, 3- or 4-amino-N,N-di-n-butyl-benzamide,

2-, 3- or 4-amino-benzoic acid morpholide, 2-, 3- or 4-amino-benzanilide,

2-, 3- or 4-amino-N-methyl-benzanilide,

2-, 3- or 4-amino-phenyl methyl sulfone,

2-, 3- or 4-amino-benzyl methyl sulfone, 2-, 3- or 4-amino-phenethyl methyl sulfone,

3-(4'-amino-phenyl)-propyl methyl sulfone,

2-(4'-amino-phenyl)-propyl methyl sulfone,

1-(2'-amino-phenethyl)-tetramethylene-sulfone,

2-, 3- or 4-amino-phenyl γ-methylsulfonyl-propyl ether,

2-, 3- or 4-amino-phenyl methylsulfonate,

2-, 3- or 4-amino-phenyl ethylsulfonate,

2-, 3- or 4-amino-phenyl β-chloro-ethylsulfonate,

2-, 3- or 4-amino-phenyl butylsulfonate,

2-, 3- or 4-amino-phenyl n-hexylsulfonate,

2-, 3- or 4-amino-phenyl phenylsulfonate,

2-, 3- or 4-amino-phenyl 4'-methyl-phenylsulfonate,

2-, 3- or 4-amino-phenyl 4'-methoxy-phenylsulfonate,

2-, 3- or 4-amino-phenyl N,N-dimethylsulfamate,

2-, 3- or 4-amino-phenyl N,N-diethylsulfamate,

2-, 3- or 4-amino-phenyl N,N-di-n-butylsulfamate,

2-, 3- or 4-amino-benzene-sulfonamide,

2-, 3- or 4-amino-benzene-N-methyl-sulfonamide,

2-, 3- or 4-amino-benzene-N,N-dimethyl-sulfonamide,

2-, 3- or 4-amino-phenylsulfonyl-ethylenimine,

2-, 3- or 4-amino-benzene-N,N-diethyl-sulfonamide, 2-, 3- or 4-amino-benzene-N,N-di-n-butyl-sulfonamide,

2-, 3- or 4-amino-benzene sulfonic acid morpholide,

2-, 3- or 4-amino-benzene sulfonic acid anilide,

2-, 3- or 4-amino-benzene sulfonic acid N-methyl-anilide,

1-methoxy-2-amino-benzene-4-N,N-dimethyl-sulfonamide,

1-methoxy-2-amino-benzene-4-sulfonamide,

1-methoxy-2-amino-benzene-4-sulfonic acid N-methylanilide,

1-chloro-2-amino-benzene-4N,N-dimethylsulfonamide,

1-chloro-4-amino-benzene-2-N,N-dimethylsulfonamide,

2-, 3- or 4-amino-acetanilide,

2-, 3- or 4-amino-N-(β-butoxy-propionyl)-aniline,

1,2-, 1,3- or 1,4-N-phenoxyacetyl-phenylene-diamine,

2-, 3- or 4-amino-N-methyl-acetanilide,

N-(4-amino-phenethyl)-γ-butyrolactam,

N-methyl-α-(4-amino-phenethyl)-γ-butyrolactam,

N-methyl-α-(4-amino-β-phenpropyl)-γ-butyrolactam,

N-(4-amino-phenethyl)-ε-caprolactam,

4-amino-diphenyl,

ethyl 4-amino-diphenyl-4'-carboxylate,

4-amino-diphenyl-methan,

4-amino-diphenyl-dimethyl-methan,

1-amino-naphthaline,

8-chloro-1-amino-naphthaline,

5-nitro-1-amino-naphthaline,

2-amino-naphthaline,

5-nitro-2-amino-thiazole,

Suitable coupling components in the meaning of the above formula are, for instance, the derivatives of the following 6-hydroxy-pyridones that are substituted in the 3-position by cyano:

1-methyl-6-hydroxy-2-pyridone,

1-phenyl-6-hydroxy-2-pyridone,

1-methyl-4-methyl-6-hydroxy-2-pyridone,

1-ethyl-4-methyl-6-hydroxy-2-pyridone,

1-n- or iso-propyl-4-methyl-6-hydroxy-2-pyridone,

1-n- iso- or sec.-butyl-4-methyl-6-hydroxy-2-pyridone,

1-n- or iso-amyl-4-methyl-6-hydroxy-2-pyridone,

1-n-hexyl-4-methyl-6-hydroxy-2-pyridone,

1-(2'-dimethylamino- or diethylamino-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-cyano-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-hydroxy-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-acetoxy-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-phenoxy-acetoxy-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(1'-methyl-2'-hydroxy-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(3'-hydroxy-propyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-phenoxy-ethyl)-4-methyl-6-hydroxy-2-pyridone,

1-(3'-methoxy-propyl)-4-methyl-6-hydroxy-2-pyridone,

1-cyclohexyl-4-methyl-6-hydroxy-2-pyridone,

1-benzyl-4-methyl-6-hydroxy-2-pyridone,

1-(3'-methyl-benzyl)-4-methyl-6-hydroxy-2-pyridone,

1-phenyl-4-methyl-6-hydroxy-2-pyridone,

1-(2'- or 4'-methyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2',4'-dimethyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-chloro-4'-methylphenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'- or 4'-chlorophenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'- or 4'-methoxy-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2',5'-dimethyl-4'-chloro-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-[4'-(3"-methyl-sulfonyl-propyl)-phenyl]-4-methyl-6-hydroxy-2-pyridone

of the formula ##SPC5##

1-[4'-(2"-N-ε-caprolactam)-ethyl]-phenyl-4-methyl-6-hydroxy-2-pyridone of the formula ##SPC6##

1-{4'-[2"-(α-N-methyl-γ-butyrolactam)-ethyl]-phenyl}-4-methyl-6-hydroxy-2-pyridone of the formula ##SPC7##

1-(2'-, 3'- or 4'-ethoxycarbonyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-acetyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-benzoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-dimethyl-carbamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-diethyl-carbamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

-(-(2'-, 3'-or 4'-iso-propyl-carbamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-methylsulfonyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-phenylsulfonyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-dimethylsulfamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-iso-propylsulfamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone,

1-(2'-, 3'- or 4'-diethylsulfamoyl-phenyl)-4-methyl-6-hydroxy-2-pyridone.

Further suitable coupling components are those 3-cyano-6-hydroxy-pyridones containing in the 4-position instead of the methyl group an ethyl, n- or isopropyl, n-, iso- or sec.butyl, n- or isoamyl, n-hexyl, cyclohexyl, benzyl, phenyl, 4'-methyl-phenyl, or an ethoxycarbonyl group or the residue --CH₂ --COOCH₃. Likewise suited are the derivatives of these pyridones wherein the cyano group in the 3-position is replaced by a nitroso, nitro, methyl, ethyl n- or isopropyl, n-, iso-or sec. butyl, n- or isoamyl, n-hexyl, cyclohexyl, benzyl or phenyl group or by one of the following residues:

3-methyl carboxylate,

3-ethyl carboxylate,

3-n- or iso-propyl carboxylate,

3-n-, iso- or sec.-butyl carboxylate,

3-n- or iso-amyl carboxylate,

3-n-hexyl carboxylate,

3-acetyl,

3-propionyl,

3-capronyl,

3-capryl,

3-hexahydrobenzoyl,

3-phenacetyl,

3-benzoyl,

3-(4'-methyl-benzoyl),

3-(2', 4'-dimethyl-benzoyl),

3-(4'-methoxy-benzoyl),

3-(4'-chloro-benzoyl),

3-carbonamide,

3-N-methyl-carbonamide,

3-N,N-dimethyl-carbonamide,

3-N-carbonyl ethylenimine,

3-N-ethyl-carbonamide,

3-N-isopropyl-carbonamide,

3-N,N-diethyl-carbonamide,

3-N-hydroxyethyl-carbonamide,

3-N-γ-methoxypropyl-carbonamide,

3-carboxylic acid morpholide,

3-carboxylic acid piperidide,

3-N-cyclohexyl carbonamide,

3-N-benzyl-carbonamide,

3-carboxylic acid anilide,

3-carboxylic acid-(4'-methyl-anilide),

3-carboxylic acid (N-methyl-anilide),

3-methylsulfonyl,

3-ethylsulfonyl,

3-n- or iso-propylsulfonyl,

3-n-, iso- or sec.-butylsulfonyl,

3-n- or iso-amylsulfonyl,

3-n-hexylsulfonyl,

3-benzylsulfonyl,

3-phenylsulfonyl,

3-(4'-methyl-phenyl)-sulfonyl,

3-(2',4'-dimethyl-phenyl)-sulfonyl,

3-(4'-methoxy-phenyl)-sulfonyl,

3-(4'-chloro-phenyl)-sulfonyl,

3-sulfonamide,

3-N-methylsulfonamide,

3-N,N-dimethylsulfonamide,

3-N-sulfonyl-ethylenimine,

3-N-ethylsulfonamide,

3-N-isopropylsulfonamide,

3-N,N-diethylsulfonamide,

3-N-hydroxyethylsulfonamide,

3-N-γ-methoxypropylsulfonamide,

3-sulfonic acid morpholide,

3-sulfonic acid piperidide,

3-N-cyclohexylsulfonamide,

3-N-benzylsulfonamide,

3-sulfonic acid anilide,

3-sulfonic acid (4' -methyl-anilide),

3-sulfonic acid (N-methyl-anilide).

Particularly valuable dyestuffs are those the diazo component of which derive from 3-amino-phenyl phenylsulfonate, 3-amino-phenyl p-tolylsulfonate, 3-amino-phenyl p-anisylsulfonate and 4-amino-benzophenone in combination with a 1-(C₁ -C₄)-alkyl or 1-methoxypropyl-3-cyano-4-methyl-6-hydroxy-2-pyridone as coupling component.

The dyestuffs of the present invention are excellently suited for the dyeing and printing of fabrics made from synthetic materials, such as polyacrylonitrile, polyamide, cellulose 2 1/2 acetate, cellulose triacetate and particularly polyester materials such as those on the basis of polyethylene glycolterephthalate. When applied according to the usual dyeing and printing methods onto these materials they yield deep dyeings and full prints showing yellow to red shades and having very good fastness properties, in particular an excellent fastness to light and sublimation.

Dyes of the above described kind and having in the 3-position a cyano group yield dyeings and prints of particularly good dyeing properties.

Dyeing of said materials with the dyes of the present invention is advantageously performed from an aqueous suspension in the presence of carriers at temperatures of between about 80° and 110°C. in the absence of carriers between about 110°C and 140°C and also according to the so-called thermofixing process at about 170°C. to 230°C. Printing can be carried out in such a manner that the materials, after being printed, are steamed in the presence of a carrier at about 80°C. to 110°C. or in the absence of a carrier at about 110°C. to 140°C. or alternatively are treated according to the so-called thermofixing process at about 170°C. to 230°C.

Typical preparations are described in the following Examples where all temperatures are in degrees Centigrade and all parts are parts by weight.

EXAMPLE 1

21.6 parts 3-amino-phenyl N,N-dimethylsulfamate are dissolved in 300 parts of water with the addition of 36 parts of a 30% hydrochloric acid and diazotized at 0° to +5° with a solution consisting of 7,7 parts sodium nitrite dissolved in 50 parts of water. The diazo solution is allowed to run into a solution consisting of 18,0 parts 1-methyl-3-cyano-4-methyl-6-hydroxy-2-pyridone dissolved in 400 parts of water, 18,2 parts of sodium hydroxide solution (33° Be) and 36.0 parts of sodium acetate; during the coupling process the reaction temperature is kept at 0° to +5° by the addition of 500 parts of ice. The coupling process being terminated, the dyestuff so formed is sucked off, washed with water until neutral and finally dried. The dyestuff constitutes a yellow powder dissolving in concentrated sulfuric acid with a reddish yellow color. It has a melting point of 196° to 197°.

The 1-methyl-3-cyano-4-methyl-6-hydroxy-2-pyridone required as intermediate may be prepared, for instance, by condensation of methyl acetoacetate with N-methyl-cyanoacetamide in an aqueous alkaline medium at room temperature. It constitutes a colorless powder melting at 280° to 282°.

1.0 parts of the finely dispersed dyestuff obtained according to the above prescription and having the formula ##SPC8##

are stirred into 2000 parts of water. The reaction mixture is adjusted with acetic acid to a pH-value of 5 to 6 and admixed with 4 g. ammonium sulfate and 2 g. of a commercial dispersing agent on the basis of a naphthalene sulfonic acid formaldehyde condensate. 100 parts by weight of a polyester fabric on the basis of polyethylene glycolterephthalate are introduced into the thus obtained dye bath and dyed during 1 1/2 hours at 120° to 130°. After subsequent rinsing, reductive aftertreatment with a 0.2% alkaline sodium dithionite solution during 15 minutes at 60° to 70° rinsing and drying, there is obtained a greenish yellow dyeing having very good fastness properties, especially a very good fastness to light.

The following table enumerates further dyestuffs of the present invention that are prepared according to the above prescription. The ultimate column indicates the shades obtained with the respective dyestuffs when dyed or printed on polyester fibers. All the enumerated dyestuffs have very good fastness properties. ##SPC9##

EXAMPLE 2

16.5 parts ethyl 4-amino-benzoate are dissolved in 300 parts of water with the addition of 36 parts of a 30% hydrochloric acid, diazotized according to the prescription given in para 1 of Example 1, coupled with 24.9 parts of 1-phenyl-3-cyano-4-methyl-6-hydroxy-2-pyridone and the dyestuff being formed is isolated. The dyestuff constitutes a yellow powder that dissolves in concentrated sulfuric acid with a reddish yellow color. It melts with decomposition at 269°.

The 1-phenyl-3-cyano-4-methyl-6-hydroxy-2-pyridone required as intermediate is obtained by condensation of acetoacetanilide with methyl cyano acetate or of methyl aceto acetate with cyanoacetanilide in ethanol with the addition of potassium hydroxide at 85°. This pyridone derivative constitutes a colorless substance melting with decomposition at 313° to 315°.

A fabric made from polyethylene glycolterephthalate is padded at 30° on the padding machine with a liquor containing 20,0 parts of the finely dispersed dyestuff of the formula ##SPC10##

which is prepared as described above, 1.0 parts polyacrylamide having a k-value of 120 and 0.5 parts of a polyglycol ether of the oleyl alcohol and 978,5 parts of water. After drying, the dyeing is fixed during 60 seconds at 210° on the thermofixing frame. After subsequent rinsing and working up as described in para 3 of Example 1, there is obtained a greenish yellow dyeing having excellent fastness properties.

The following table enumerates further dyestuffs of the present invention that are prepared according to the above description. Their dyeings and prints on polyester materials show very good fastness properties. ##SPC11##

EXAMPLE 3

21.6 parts 4-amino-phenyl N,N-dimethylsulfamate are diazotized as described in para 1 of Example 1, coupled with 24.4 parts 1-(3'-methoxy-propyl)-3-cyano-4-methyl-6-hydroxy-2-pyridone and the dyestuff being formed is isolated. The dyestuff constitutes a yellow powder that dissolves in concentrated sulfuric acid with a reddish yellow color. It has a melting point of 178° to 182°.

The 1-(3'-methoxy-propyl)-3-cyano-4-methyl-6-hydroxy-2-pyridone required as intermediate for the preparation of the above dyestuff is obtained for instance by condensation of methyl aceto-acetate with cyano-acetic acid-(3'-methoxy-propylamide) in ethanol with the addition of potassium hydroxide at 85°. It constitutes a colorless powder melting at 198° to 199°.

30 parts of the dyestuff (calculated on 1000 g. of a printing paste) of the formula ##SPC12##

the preparation of which is described above, are incorporated in a finely divided form into a printing paste containing 45.0 parts locust bean meal, 6.0 parts sodium 3-nitro-benzenesulfonate and 3.0 parts citric acid. This printing paste, when applied onto a polyester fabric, yields after printing, drying and fixing on the thermofixing frame during 45 seconds at 215°, subsequent rinsing and working up as described in para 3 of Example 1 greenish yellow prints having very good fastness properties.

The dyestuff yields in the printing of triacetate fabrics, if employed in the form of the above described printing paste, and the printed fabric is steamed, after drying, for 10 minutes at a superatmospheric pressure of 1,5 atmospheres, subsequently rinsed, soaped, rinsed again and dried, a greenish yellow print having a very good fastness to light.

The following table enumerates further dyestuffs of the present invention as well as their shades when applied onto polyester materials. ##SPC13##

EXAMPLE 4

26.2 parts 3-amino-benzene-sulfonic acid N-methyl-anilide are diazotized and coupled as described in para 1 of Example 1. The isolated dyestuff constitutes a yellow powder that dissolves in concentrated sulfuric acid with a greenish yellow color. It has a melting point of 253° to 255°.

30 parts of the above described dyestuff (calculated on 1000 g. of a printing paste) of the formula ##SPC14##

are incorporated in a finely dispersed form into a printing paste containing 16.0 parts of an alginate thickener and 20.0 parts of a starch ether. This printing paste, when applied onto a polyester fabric yields, after printing, drying and fixing on the thermofixing frame during 60 seconds at 220°, subsequent rinsing and working up as described in para 3 of Example 1, a greenish yellow print having very good fastness properties.

The following table enumerates further dyestuffs of the present invention as well as their shades when applied onto polyester material. ##SPC15## 

What is claimed is:
 1. A monoazo dye of the formula ##SPC16##wherein R is monosubstituted phenyl whose substituent is selected from the group consisting of --OSO₂ CH₃, --OSO₂ -phenyl, --OSO₂ C₂ H₅, --OSO₂ C₂ H₄ Cl, --OSO₂ C₄ H₉, --OSO₂ C₆ H₁₃, ##SPC17##and ##SPC18## X is alkyl having from 1 to 6 carbon atoms and Z is alkyl having from 1 to 6 carbon atoms or methoxyalkyl or hydroxyalkyl having from 1 to 6 carbon atoms in each alkyl moiety.
 2. The monoazo dye of claim 1 wherein X is methyl.
 3. The monoazo dye of claim 1 wherein R is ##SPC19##
 4. The monoazo dye of claim 1 wherein R is ##SPC20##and X and Z are methyl. 